About the VNT

[Rabbit on Roids]

vanes are restricting flow? the only way my turbo could be any more free flowing, is if the vanes were completely removed. my vanes are open. pointing directly at the middle of the turbine wheel.

if you have the vanes closed, the turbo SCREAMS and makes almost 40 psi. this is not good. i learned this the hard way.

its better to have them all the way open, than all the way closed. its gotta mane a TON of drive pressure to have them closed, but ive never checked..

[OM617]

vanes are restricting flow? the only way my turbo could be any more free flowing, is if the vanes were completely removed.

Exactly. When functional they are a beneficial compromise because of how tremendiously they help increase response performance. Inoperable they impede flow by adding obstructions and odd angles to the exhaust stream and drastically increase surface area absorbing heat energy.

pointing directly at the middle of the turbine wheel.

Which is the worst option. That forces the exhaust to make a tight turn into an inefficient angle of the wheel instead of hitting the turbine at a 45* angle as with a normal non-VNT turbo.

if you have the vanes closed, the turbo SCREAMS and makes almost 40 psi.

Um, thats why people build a system to control it. 

its better to have them all the way open

Without something to control the vanes, its better to have a normal non-VNT turbo.

[Rabbit on Roids]

ok, well whatever you have to say, it doesnt matter. theres a VNT 17 on my car.. its faster then your rabbit. oh yea, your a stuck up mercedes benz driver..

do you ever have anything to say that is positive? rather than just negative all the time? its pretty sad when you have ME saying something about it..

why not give out some suggestions/solutions? rather than just point out someones/somethings short comings?

im aware my turbo could function better if the variable vanes were hooked up. but, it functions fine for me right now. the vanes are all coked up and dont really move anymore. thats why its never been hooked up right.

and if i had the vanes closed 50% so they were at 45* angles to the turbine, it would over speed and make around 35 psi. thats not what im looking for.

look at it this way: i got the car for free, i got the turbo for free, i have fun driving it.. thats all that should matter.

[OM617]

oh yea, your a stuck up mercedes benz driver.

Ah, insults. The favorite fallback of people with nothing intelligent to say in a debate.

do you ever have anything to say that is positive?

Did you ever stop to think about what I reply to? If people do something bad or post something thats wrong, what else is there to say?

why not give out some suggestions/solutions?

As was done multiple times in all of my replies to you.

rather than just point out someones/somethings short comings?

Oh, so you won't have any opportunity to think for yourself or make your own decisions derived from the facts you learn?

the vanes are all coked up and dont really move anymore. thats why its never been hooked up right.

I recall an old saying, "If you're going to do something, do it right from the start".

[burn_your_money]

Moving on....

[fatmobile]

Boost is around 20psi because it cant flow any more air! All you're doing is overspeeding the turbo and putting your engine's life at risk.

 He'll only respond if we haven't proven him wrong.
 When he can't back up what he says he leaves, with no reply.

 So you think a VNT-15 will only push 20psi? There he's gone.
Or wait, here's one he couldn't back up last time.
All factory VNTs setups have the vanes closed when you are idleing.  really?,.. now he's really gone

 The car wasn't floored going 80, and the turbo wasn't pushed to it's limit.
 Concidering that, does it now sound optimal during heavy acceleration?

He does make some good points, but you have to sort them from the pompous garbage.

ROR, sorry, I thought with boost like that the vanes would have to be closed some.
Sounds like a VNT-17 is too big for a 1.6 Rabbit.
 When the vanes are pointed at the wheel, they are closed.
 Open, they make a ring around the wheel.

So maybe when he says the vanes will restrict flow with them wide open, he is thinking you mean wide assed closed.
I used to mix them up, then just concidered the wording like a wastegated turbo.
 Closed is more air, open is less.

 I can't match the vague old sayings that readily applies to guys who tried to get everything right from the start,
 but due to time constraints now have a stripped down project for sale,
 while I drive my car.
they'll never get it finished because everything has to be perfect from the start, ha.

I am messing with another controller, one that's not related to the accelerator lever.
 I want a manual knob on my dash that will let me set it to a general area, then let the boost controller do the rest.

[MJF]

VNT flows most when vanes are open. When vanes are closed, it will choke flow and raise EMP and boost. 17īs are not big when fueling is right. I had vnt20 from V6 TDI in my 1,6, I could not get boost below 30psi with max fuel.

[OM617]

I'll only respond if I have something completely worthless to say.
 When I can't think of anything intelligent to say I reply, frequently.

So you think a VNT-15 will only push 20psi?

RELIABLY. BAM, you've been proven wrong yet you're still here? Good.

All factory VNTs setups have the vanes closed when you are idleing.

Yes. All of them. Have you actually LOOKED at any VNT/VGT systems to see what they are doing? Do you have a computer that tells you the exact vane position in real time? Thought not.

Got anything that will give you this kind of data?

Time 51:38.3
EGR Valve Position (Percent Open) (Percent) 10
Engine Coolant Temperature (F) 189.4
Engine Oil Pressure (psi) 18.4
Engine Oil Temperature (F) 206.6
Engine Speed (RPM) 692
Exhaust Gas Pressure (InHg) 47.6
Exhaust Gas Temperature (Calculated) (F) 555
Intake Manifold Air Temperature (F) 102
Intake Manifold Pressure (InHg) 1.9
Percent Accelerator (Percent) 0
Percent Fuel (Percent) 28
Turbocharger Compressor Outlet Air Temperature (Calculated) (F) 71
Turbocharger Control Valve Command (Percent) 70
Turbocharger Speed (RPM) 25800
User Fueling State: Low Speed Governor State
Vehicle Speed (mph) 0

ROR, sorry, I thought with boost like that the vanes would have to be closed some.

It does. My GT22 is lucky to hit 12psi with the vanes open no matter how much black smoke my 3.0L engine pukes through it. No way a GT17 can do 20psi on a 1.6L.

When the vanes are pointed at the wheel, they are closed.

Wrong.

Open, they make a ring around the wheel.

Wrong.

[Vincent Waldon]

Howsabout everybody simmer down and remember that:

1) these are just cars and engines... nothing worth duelling to the pain over...
2) we're here to learn from each other and share information, not prove who's the smartest or best endowed
3) the forum guidelines call for respectful posts at *all* times.

[Rabbit on Roids]

It does. My GT22 is lucky to hit 12psi with the vanes open no matter how much black smoke my 3.0L engine pukes through it. No way a GT17 can do 20psi on a 1.6L.

I've seen a VNT17 on a 1.6 make over 20 psi with the vanes wide open, no visible smoke and EGTs under 900 degrees.

i own a car that will put down 25 psi, no smoke.. WORN OUT VNT 17!

is that not proof enough? how is it not possible? if i own a car that will hit 20 psi at my any whim? what do you say about that? is it still impossible to get 20+ psi from a 17? i wish i knew EVERYTHING..

i still dont get how my car runs, and makes boost, but its impossible?

and how did i crack a block? not from too much boost and drive pressure surely..

piss off OM617.. you have nothing useful to add to this, or any other conversation..